Peoria Air Quality in May
Across 2019–2025, Peoria's May air quality had a median AQI of 46 (Good) over 217 monitored days in the Peoria, IL area. 2.8% of May days (6 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 76.5% of days. The cleanest May on record here was 2020 (median AQI 39, 0 days above 100) and the worst was 2023 (median 66, 6 days above 100, peak AQI 151).
- Good: 66.4%
- Moderate: 30.9%
- Unhealthy for Sensitive Groups: 2.3%
- Unhealthy or worse: 0.5%
Improve Indoor Air Quality
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How is the air in Peoria in May?
Good on a typical day: median AQI 46 across 2019–2025, with 2.8% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓66.4% of May days were Good (AQI 0–50), 30.9% Moderate (51–100).
- ✓6 days of 217 reached AQI 101+; the May peak was 151.
- ✓Best May: 2020; worst May: 2023.
Frequently asked questions
What is the air quality like in Peoria in May?▾
Across 2019–2025, the median daily AQI in Peoria in May was 46 (Good). 66.4% of days were Good, 30.9% Moderate, and 2.8% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Peoria?▾
A typical May day in Peoria sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 36 of May days (2.8%) reached AQI 101+ in 2019–2025.
Which pollutant causes Peoria's May air quality problems?▾
Ground-level ozone set the daily AQI on 76.5% of May days in Peoria. The highest May AQI recorded in 2019–2025 was 151 (Unhealthy), in 2023.
Peoria May air quality, year by year
Peoria May air quality by year (Peoria, IL, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 42 | 0 | 61 | O3 |
| 2020cleanest | 31 | 39 | 0 | 49 | O3 |
| 2021 | 31 | 47 | 0 | 61 | PM2.5 |
| 2022 | 31 | 47 | 0 | 80 | O3 |
| 2023worst | 31 | 66 | 6 | 151 | O3 |
| 2024 | 31 | 47 | 0 | 77 | O3 |
| 2025 | 31 | 44 | 0 | 84 | O3 |
What May air means in Peoria
A typical May day in Peoria sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 36 of May days (2.8%) reached AQI 101+ in 2019–2025.
May's median AQI of 46 is in line with Peoria's whole-year median of 45, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Peoria runs in line with the national May norm; 2.8% of its May days topped AQI 100 versus 1.3% nationally (above average).
May is part of Peoria's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Peoria
The latest EPA AirNow observation puts Peoria's AQI at 42 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Peoria air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Peoria, IL), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.